138 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



EXPLANATION OF PLATE IV. 



Page. 



Desmoceras ashlandicum, sp. nov. 100 



Figs. 107-109. Young adult shells. 

 Schloenbachia buitcnsis, sp. nov. 118 



Fig. no. Full grown shell. 



Fig. III. Section of whorl. 



Phylloceras shastalense, sp. nov. 80 



Figs. 1 1 2-1 13. Mature shells. 



Figs. 114-115. Younger shells. 

 Desmoceras dilleri, sp. nov. 97 



Figs. 116-117. Mature shells. 

 Desmoceras subquadratuin, sp. nov. 96 



Figs. 118-119. Young adult shells. 



